1. Field of the Invention
The present invention relates to a compact camera module, particularly, a compact camera module installed in an electronic device such as a cellular phone.
2. Description of the Related Art
FIG. 1 is a partial cross-sectional view of a compact camera module 1 of the related art. In the compact camera module 1, a square circuit board 3, on which a CCD solid image pickup device 2 is mounted, is attached to the bottom of a lens unit 4. The lens unit 4 includes a cylindrical lens holder 13 in which lenses 10 and 11 and an optical filter 12 are accommodated, and a housing 14 having an upper cylindrical portion 14a and a lower box-shaped portion 14b. The lens holder 13 is fastened to the cylindrical portion 14a of the housing 14 by threads 15. If tuning the lens holder 13, the lens holder 13 moves along an optical axis, thereby adjusting the focus point of the compact camera module 1. This compact camera module 1 is mounted on a mounting board.
If dust adheres to the surface 2a of the CCD solid image pickup device 2, the quality of the obtained image is degraded. In addition, because the surface 2a of the CCD solid image pickup device 2 is formed by a micro-lens structure and is delicate, it is not easy to remove away the dust adhering to the surface 2a. Therefore, it is important to prevent dust from adhering to the surface 2a of the CCD solid image pickup device 2.
Japanese Laid Open Patent Application No. 2001-188155 discloses a technique related to this issue.
One problem with the cameral module 1 shown in FIG. 1 is that, when assembling the cameral module 1 after the CCD solid image pickup device 2 is mounted on the circuit board 3, the CCD solid image pickup device 2 is exposed to atmosphere until the circuit board 3 is attached to the bottom of the lens unit 4, and dust may adhere to the surface 2a of the CCD solid image pickup device 2 in the assembling process. This caused a problem in production of the compact camera module in a large quantity.